Benefits
Well-Absorbed Chelated Form
A single small crossover trial (Gandia 2007, 12 healthy women, single 15 mg dose) found zinc bisglycinate raised serum zinc 43.4% more than an equal dose of zinc gluconate. A 2024 narrative review in Nutrients (Devarshi et al.) concluded that zinc glycinate and zinc gluconate are both better absorbed than other zinc forms; it does not single out bisglycinate as superior to gluconate. The bisglycinate advantage is measured as blood zinc, a pharmacokinetic surrogate, not a clinical outcome.
GI Tolerability (Chelate Form)
The chelate structure protects zinc through gastric pH changes and from competing absorption inhibitors. Causes less GI distress than zinc sulfate or high-dose oxide. Better tolerated for chronic dosing.
Immune Support
Zinc supports T-cell function, NK cell activity, and inflammatory cytokine balance. Adequate zinc status critical for proper immune response.
Skin and Wound Healing (General Zinc Role)
Zinc has a general role in skin integrity and wound healing, and correcting zinc deficiency helps these processes. No trial has tested zinc bisglycinate specifically for a skin or wound-healing outcome.
Reproductive Health
Zinc is critical for sperm production, ovulation, and reproductive hormone regulation. Zinc deficiency contributes to infertility; supplementation in deficient populations supports reproductive function.
Mechanism of action
Chelate Stability and Absorption
Bisglycinate structure: zinc ion bonded to two glycine molecules forming a 5-membered ring. Stable through gastric pH; absorbed via dipeptide transporters in addition to standard zinc transporters (ZIP family).
Reduced Absorption Inhibition
Phytates (in grains, legumes) and oxalates (in spinach, etc.) inhibit zinc absorption from typical zinc salts. Chelation protects zinc from these inhibitors — allowing better absorption when taken with meals.
Glycine Synergy (Theoretical)
Glycine itself supports collagen synthesis and immune function. Some theoretical synergy proposed though clinical evidence specific to glycine contribution is limited.
Standard Zinc Functions
All zinc forms share same fundamental biology — cofactor for >300 enzymes, zinc finger transcription factors, immune function, antioxidant via Cu/Zn-SOD.
Clinical trials
Randomized crossover study comparing zinc bisglycinate (15 mg elemental) vs zinc gluconate (15 mg elemental) for serum zinc pharmacokinetics; single-dose crossover.
12 healthy female volunteers, single-dose crossover.
Zinc bisglycinate produced significantly higher serum zinc Cmax and AUC than gluconate, a 43.4% increase. This is a single small study (n=12) measuring blood zinc, a pharmacokinetic surrogate, not a clinical outcome.
Evidence review comparing absorption and bioavailability of zinc acetate, citrate, glycinate, gluconate, oxide, picolinate, sulfate in human studies.
Not a single study; narrative review of human zinc pharmacokinetic studies (Devarshi et al. 2024, Pharmavite-funded).
Zinc glycinate and zinc gluconate ranked best-absorbed across human trials. Zinc oxide consistently worst. Picolinate competitive but not consistently superior.